当课程简介内容很少时（点击显示更多没有反应），取消显示更多按钮的显示

app/views/layouts/base_courses.html.erb

@@ -150,9 +150,11 @@
       <div class="project_intro">
         <div id="course_description" class="course_description">
           <h4 ><%= l(:label_course_brief_introduction)%>：</h4>
-          <%= textilizable(@course.description) if @course.description && !@course.description.blank? %>
+          <div id="course_description_content">
+            <%= textilizable(@course.description) if @course.description && !@course.description.blank? %>
+          </div>
         </div>
-        <div class="lg-foot" onclick="show_more_msg();">
+        <div class="lg-foot" id="lg-foot" onclick="show_more_msg();">
           <%= l(:label_expend_information)%>
           <span class="g-arr-down">
             <img src="/images/jiantou.jpg" width="12" height="6" />

public/javascripts/course.js

@@ -151,3 +151,11 @@ function hidden_atert_form(cur_page,cur_type)
 {
     hideModal($("#popbox"));
 }
+
+$(function(){
+    alert($("#course_description_content").height());
+    if($("#course_description_content").height()>112)
+    {
+        $("#lg-foot").show();
+    }
+});

public/stylesheets/leftside.css

@@ -46,7 +46,7 @@ a:hover.subnav_green{ background:#14ad5a;}
 .project_intro{ width:220px; padding:10px; background:#fff; margin-top:10px; padding-top:5px; color:#6d6d6d; line-height:1.9;}
 .course_description{max-height: 112px;overflow:hidden;}
 .course_description_none{max-height: none;}
-.lg-foot{ border:1px solid #e8eef2; color: #929598; text-align:center; width:220px; height:23px; cursor:pointer;}
+.lg-foot{ border:1px solid #e8eef2; color: #929598; text-align:center; width:220px; height:23px; cursor:pointer;display: none;}
 .lg-foot:hover{ color:#787b7e; border:1px solid #d4d4d4;}
 /****标签(和资源库的tag样式一致)***/
 .project_Label{ width:220px; padding:10px; background:#fff; margin-top:10px;  padding-top:5px; margin-bottom:10px;}